ABSTRACT
This chapter discusses the null and alternative hypotheses in its concepts, notations, and interpretations. It focuses on the concept of directional and nondirectional research hypotheses. In the context of research, a hypothesis is tested to measure the significance of an evidence for a claim about a population using inferential statistics. The null hypothesis states "no effect," "no difference," or "no relationship." Conversely, the alternative hypothesis states that there is a: "significant effect," "significant difference," or "significant relationship." In the absence of no effect, the null hypothesis would be true. A researcher's "expectation" is called a research hypothesis. Because the research hypothesis states that one particular group's average is higher than the other groups, this research hypothesis is known as a directional research hypothesis. A nondirectional research hypothesis is also a possibility. The null hypothesis is a possible explanation for an observed difference when there are sampling errors.
